1. Department of Family Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul 110-746, Korea.
2. Medical Research Center, Sungkyunkwan University School of Medicine, Suwon 440-746, Korea.
3. Department of Medical Nutrition, Graduate School of East-West Medical Science, Kyung Hee University, Yongin 447-701, Korea.
4. Research Institute of Medical Nutrition, Kyung Hee University, Seoul 130-701, Korea.